The present disclosure relates to a recording medium cartridge with an improved reliability on an unintentional deletion prevention mechanism. In recent years, a disk cartridge that rotatably accommodates a disk-like recording medium such as an optical disc, a magneto optical disc, and a magnetic disk is widely used. In general, a disk cartridge is capable of recording and/or reproducing information signals including music signals, video signals, and programs. As such a disk-like recording medium capable of recording information signals, there are known, for example, a writable write-once disc and a rewritable disc with which rewrite is possible.
The disk cartridge of this type includes an unintentional deletion prevention mechanism for setting whether information can be recorded onto the disk-like recording medium. Patent Document 1 discloses, for example, a structure of an unintentional deletion prevention mechanism including an erroneous deletion preventing member that is slidable with respect to a cartridge main body and a detection hole formed on the cartridge main body.
The erroneous deletion preventing member selectively takes a recordable position at which information can be recorded onto a disk-like recording medium and an unrecordable position at which information cannot be recorded onto the disk-like recording medium. The detection hole is opened and closed in accordance with a movement of the erroneous deletion preventing member between the recordable position and the unrecordable position. Opened and closed states of the detection hole are detected by a drive apparatus (recording/reproducing apparatus) into which the disk cartridge is loaded. As a result, it becomes possible to prevent information from being recorded unintentionally onto the disk-like recording medium or information recorded onto the disk-like recording medium from being deleted unintentionally at a time the erroneous deletion preventing member is at the unrecordable position.
The erroneous deletion preventing member moves along a guide wall formed inside the cartridge main body. The erroneous deletion preventing member includes an elastic engagement part that elastically comes into contact with a side surface of the guide wall. On the side surface of the guide wall, a recording permission engagement recess and a recording inhibition engagement recess that engage with the elastic engagement part at a time the erroneous deletion preventing member is at the recordable position and the unrecordable position, respectively, are formed. Between the recording permission engagement recess and the recording inhibition engagement recess is a flat linear surface.
Patent Document 1: Japanese Patent Application Laid-open No. 2007-95206 (paragraphs [0045] to [0051], FIGS. 13 to 16)
In the unintentional deletion prevention mechanism of the related art described above, the guide wall that guides the movement of the erroneous deletion preventing member has a flat linear surface between the recording permission engagement recess and the recording inhibition engagement recess. Therefore, there is an inconvenience that, when the elastic engagement part of the erroneous deletion preventing member is stopped between the recording permission engagement recess and the recording inhibition engagement recess, the erroneous deletion preventing member is detected as being at the recordable position or at the unrecordable position depending on an opening level of the detection hole, with the result that detection accuracy on whether recording is possible is significantly lowered.
In particular, there is a case where, due to an unintentional drop of the disk cartridge, the erroneous deletion preventing member is moved by the drop impact and stops between the recordable position and the unrecordable position. In this case, the inconvenience described above is apt to occur, and a reliability of the unintentional deletion prevention mechanism cannot be secured.
In view of the circumstances as described above, it is desired to provide a recording medium cartridge that is capable of securing a reliability of an unintentional deletion prevention mechanism.